NorthWestern Energy, a utility serving customers in Montana, South Dakota and Nebraska, has submitted formal requests to the Montana Public Service Commission to approve the purchase of 11 hydroelectric generating facilities totaling 633 MW and related assets from PPL Montana LLC, a wholly owned subsidiary of energy and utility holding company PPL Corp.

According to NorthWestern, the filing initiates the formal regulatory process necessary to complete the $900 million agreement between the two companies. In addition, Northwestern says it is asking permission to include the hydro assets in the utility's rate base and issue the securities necessary to complete the purchase.

The utility reports that the long-term customer benefits of this purchase include greater resource adequacy and reliability; stable and reasonable costs/prices; and a more diversified portfolio.

Subject to necessary regulatory approvals and customary closing adjustments, NorthWestern and PPL intend to complete the transaction in the third quarter of 2014.

Months after the U.S. Environmental Protection Agency released its Clean Power Plan, which will create new regulations for existing power plants, the agency says it has received loads of feedback to consider.